Around one in five people over the age of 70 in the U.S. have mild cognitive impairment (MCI), in which they experience problems with memory, language, or other mental functions. Today there are about 1.5 million elderly in [the] UK, five million in [the] USA and 14 million in Europe with such memory problems. These statistics will more than likely rise in the future due to aging populations found globally.
Some B vitamins — folic acid, vitamin B6, and vitamin B12 — control levels of the amino acid homocysteine in the blood, and high levels of homocysteine are associated with an increased risk of Alzheimer’s.
Most is known about the effects of vitamin B12 deficiency on mental status. Cognitive impairment, depression, and mania are among the symptoms. It should be noted that many of these signs and symptoms can occur when the serum B12 level is just slightly below what is considered normal and much higher than that usually associated with anemia.
Pernicious anemia develops slowly over 20-30 years. It is characterized by the body’s inability to use B12. Adult onset is one type and occurs primarily in adults older than 60 years of age; it is more common in women and in those of Northern European descent. It is due to the absence of what is called the intrinsic factor from the stomach cells. If there is no Intrinsic factor, B12 is not absorbed. Intrinsic factor often declines with age.
The bioavailability of B12 from food sources also diminishes with age and there is a decline of serum B12 to low normal levels. Adults 50 years and older should eat foods high in vitamin B12 and take vitamin supplements containing B12. Reports indicate that 0% to 50% of older living in the community do not consume the recommended amount of vitamin B12 (2.4 ug/day). B12 is found only in foods of animal origin (meats, fish, cheese, eggs) and fortified cereals and a deficiency is often associated with vegan diets.
Homocysteine-Lowering by B vitamins slows the rate of accelerated brain atrophy in mild cognitive impairment: A randomized controlled trial.
A recent study (2010) investigated the effects of these three B vitamins on the rate of brain atrophy or shrinkage and the rate of mental decline.
A randomized, double blind controlled trial was conducted with high dose of folic acid, vitamins B6 and B12 in 271 individuals over 70 years old with mild cognitive impairment. A subset of 187 subjects volunteered to have cranial MRI scans at the start and finish of the study. Participants were randomly assigned to two groups of equal size, one treated with folic acid (0.8 mg/d), vitamin B12 (0.5 mg/d) and vitamin B6 (20 mg/d), the other placebo for 24 months. The main outcome measure was the change in the rate of atrophy of the whole brain assessed by a series of MRI scans.
Results: A total of 168 participants (85 in the treatment group; 83 in the placebo group) completed the MRI section of the trial. The mean rate of brain atrophy per year was significantly less (0.76%) in the treatment group than in the placebo group (1.08%). The treatment response was related to baseline homocysteine levels. People with the highest levels of homocysteine benefited most, showing a rate of brain shrinkage that was half of those taking the placebo. A greater rate of atrophy was associated with a lower final cognitive test scores.
Delaying Alzheimer’s: Conclusions
The accelerated rate of brain atrophy in elderly with mild cognitive impairment can be slowed by treatment with homocysteine-lowering B vitamins. Sixteen percent of those over 70 years old have mild cognitive impairment and half of these develop Alzheimer’s disease within 5 years.
The research team says more trials should be carried out to see if vitamin treatment could help people at risk of Alzheimer’s.
Lead researcher David Smith of Oxford University’s department of pharmacology says in a statement: “It is our hope that this simple and safe treatment will delay the development of Alzheimer’s disease in many people who suffer from mild memory problems. Smith describes the results as “promising,” but cautions: “I wouldn’t yet recommend that anyone getting a bit older and beginning to be worried about memory lapses should rush out and buy vitamin B supplements without seeing a doctor.”
Alzheimer’s Research Trust: “Important Results”
Rebecca Wood, chief executive of the Alzheimer’s Research Trust, which co-funded the study, says in a statement: “These are very important results, with B vitamins now showing a prospect of protecting some people from Alzheimer’s in old age. The strong findings must inspire an expanded trial to follow people expected to develop Alzheimer’s, and we hope for further success.
“We desperately need to support research into dementia, to help avoid the massive increases of people living with the condition as the population ages. Research is the only answer to what remains the greatest medical challenge of our time.”
- Treatment for Vitamin B12 Deficiency Anemia (everydayhealth.com)